This is really not a big deal, and this may not be the right place to ask or report, but...

When Thunderbird downloads messages from my three email accounts into the Unified Inbox, the total number of messages that show in the red dot in the taskbar is just the number of new messages in my primary email account. This means that as new ones come into other accounts they never register in the taskbar. Is this a bug, or do I have something set up incorrectly?